The present invention relates to a measuring system for performing measurement on an object to be measured by projecting a laser beam by rotary irradiation.
As one of the surveying devices, a type of surveying device is known, by which a pulsed light (distance measuring light) for measuring distance is projected by rotary irradiation, and a distance to an object to be measured is determined by receiving and detecting a light reflected from the object to be measured. This type of surveying device is advantageous in that distances to a plurality of objects to be measured can be determined at the same time. Also, in the measuring operation, in addition to the measurement of distance, it is necessary to measure a position of the object to be measured in a horizontal direction, i.e. to measure a horizontal angle.
In a surveying device of rotary irradiation type, which has been proposed in recent years, in addition to the distance measuring light, a laser beam (a scanning light) is projected by rotary irradiation for detecting an object to be measured or to form a reference plane. The scanning light is a continuous light. The surveying device comprises a protractor (e.g. an encoder), which can continuously detect a horizontal angle in the direction where the scanning light is projected. When the scanning light is projected by rotary irradiation in the total circumference and passes through the object to be measured, a reflection light (reflected scanning light) reflected from the object to be measured is received and detected. By reading an angle of the protractor at the time of detection, a horizontal angle of the object to be measured is determined.
When the horizontal angle of the object to be measured is detected, the distance measuring light is projected within a range as required around the detected horizontal angle, and a distance is measured.
This type of surveying device is based on the detection by an optical system, which detects a reflection light from the object to be measured. In this respect, the surveying device must have structure including the need to have a photodetection optical system for the surveying device and must have complicated design. Also, the reflection light must have a light amount enough for the detection. On the other hand, the scanning light, which is a continuous light, has a limitation in the intensity of irradiation from safety reason. Accordingly, there is limitation in the distance for the purpose of confirming of the object to be measured and for the measurement of angle.